Contrast angiography provides an effective means for imaging arteries and organs during diagnostic and interventional medical procedures. The majority of such procedures are cardiac related. For example, cardiac catheterization and percutaneous transluminal coronary angioplasty (PTCA) both rely on the presence of contrast media in cardiac vessels to enable imaging during diagnostic and/or treatment procedures. Cardiac catheterization and PTCA procedures are frequently performed by inserting a catheter into the femoral artery and guiding the catheter to the ostium of a coronary artery where contrast dye is injected and cineangiography images are obtained. If severe stenosis is present, PTCA can be performed with a balloon catheter to open a blocked vessel and/or to implant one or more stents.
During an imaging procedure, iodinated contrast media is injected into a blood vessel of a patient. The contrast media causes an attenuation in an X-ray or CT beam used in the imaging procedure, thereby allowing a physician to visualize blood vessels and organs that contain the contrast material.
While contrast imaging has revolutionized diagnostic and therapeutic medical practice, it may induce renal impairment, a condition referred to as contrast-induced nephropathy (CIN). Contrast-induced nephropathy occurs when the kidneys are exposed to contrast media during imaging procedures resulting in transient or permanent renal impairment or even kidney failure.
Kidney dysfunction resulting from exposure to radiographic contrast media is believed to be a consequence of cytotoxic effects on renal tubular epithelial cells, and/or ischemic effects on the blood vessels of the renal medullary bed, induced by exposure to contrast media. Certain individuals appear to be more susceptible or at higher risk to CIN, for example, those having diabetes, or patients with baseline kidney disease.
Previous attempts to prevent or ameliorate CIN have included administering cytoprotective pharmaceutical agents, and methods that remove or reduce the concentration of contrast media in the blood including, for example, hemodialysis, hemofiltration, and hydration. Only hydration has been shown to be beneficial in preventing CIN.
There remains a need for an improved method to prevent contrast-induced nephropathy. The present invention provides an improved method for preventing CIN during an imaging procedure.